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f204e0b8 IM |
1 | /* |
2 | * Copyright 2014 IBM Corp. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | */ | |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/bitmap.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/pid.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/debugfs.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/idr.h> | |
20 | #include <asm/cputable.h> | |
21 | #include <asm/current.h> | |
22 | #include <asm/copro.h> | |
23 | ||
24 | #include "cxl.h" | |
25 | ||
26 | /* | |
27 | * Allocates space for a CXL context. | |
28 | */ | |
29 | struct cxl_context *cxl_context_alloc(void) | |
30 | { | |
31 | return kzalloc(sizeof(struct cxl_context), GFP_KERNEL); | |
32 | } | |
33 | ||
34 | /* | |
35 | * Initialises a CXL context. | |
36 | */ | |
b123429e IM |
37 | int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, |
38 | struct address_space *mapping) | |
f204e0b8 IM |
39 | { |
40 | int i; | |
41 | ||
42 | spin_lock_init(&ctx->sste_lock); | |
43 | ctx->afu = afu; | |
44 | ctx->master = master; | |
45 | ctx->pid = NULL; /* Set in start work ioctl */ | |
b123429e IM |
46 | mutex_init(&ctx->mapping_lock); |
47 | ctx->mapping = mapping; | |
f204e0b8 IM |
48 | |
49 | /* | |
50 | * Allocate the segment table before we put it in the IDR so that we | |
51 | * can always access it when dereferenced from IDR. For the same | |
52 | * reason, the segment table is only destroyed after the context is | |
53 | * removed from the IDR. Access to this in the IOCTL is protected by | |
54 | * Linux filesytem symantics (can't IOCTL until open is complete). | |
55 | */ | |
56 | i = cxl_alloc_sst(ctx); | |
57 | if (i) | |
58 | return i; | |
59 | ||
60 | INIT_WORK(&ctx->fault_work, cxl_handle_fault); | |
61 | ||
62 | init_waitqueue_head(&ctx->wq); | |
63 | spin_lock_init(&ctx->lock); | |
64 | ||
65 | ctx->irq_bitmap = NULL; | |
66 | ctx->pending_irq = false; | |
67 | ctx->pending_fault = false; | |
68 | ctx->pending_afu_err = false; | |
69 | ||
70 | /* | |
71 | * When we have to destroy all contexts in cxl_context_detach_all() we | |
72 | * end up with afu_release_irqs() called from inside a | |
73 | * idr_for_each_entry(). Hence we need to make sure that anything | |
74 | * dereferenced from this IDR is ok before we allocate the IDR here. | |
75 | * This clears out the IRQ ranges to ensure this. | |
76 | */ | |
77 | for (i = 0; i < CXL_IRQ_RANGES; i++) | |
78 | ctx->irqs.range[i] = 0; | |
79 | ||
80 | mutex_init(&ctx->status_mutex); | |
81 | ||
82 | ctx->status = OPENED; | |
83 | ||
84 | /* | |
85 | * Allocating IDR! We better make sure everything's setup that | |
86 | * dereferences from it. | |
87 | */ | |
ee41d11d | 88 | mutex_lock(&afu->contexts_lock); |
f204e0b8 | 89 | idr_preload(GFP_KERNEL); |
f204e0b8 IM |
90 | i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0, |
91 | ctx->afu->num_procs, GFP_NOWAIT); | |
f204e0b8 | 92 | idr_preload_end(); |
ee41d11d | 93 | mutex_unlock(&afu->contexts_lock); |
f204e0b8 IM |
94 | if (i < 0) |
95 | return i; | |
96 | ||
97 | ctx->pe = i; | |
98 | ctx->elem = &ctx->afu->spa[i]; | |
99 | ctx->pe_inserted = false; | |
100 | return 0; | |
101 | } | |
102 | ||
0712dc7e IM |
103 | static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
104 | { | |
105 | struct cxl_context *ctx = vma->vm_file->private_data; | |
106 | unsigned long address = (unsigned long)vmf->virtual_address; | |
107 | u64 area, offset; | |
108 | ||
109 | offset = vmf->pgoff << PAGE_SHIFT; | |
110 | ||
111 | pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n", | |
112 | __func__, ctx->pe, address, offset); | |
113 | ||
114 | if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { | |
115 | area = ctx->afu->psn_phys; | |
10a5894f | 116 | if (offset >= ctx->afu->adapter->ps_size) |
0712dc7e IM |
117 | return VM_FAULT_SIGBUS; |
118 | } else { | |
119 | area = ctx->psn_phys; | |
10a5894f | 120 | if (offset >= ctx->psn_size) |
0712dc7e IM |
121 | return VM_FAULT_SIGBUS; |
122 | } | |
123 | ||
124 | mutex_lock(&ctx->status_mutex); | |
125 | ||
126 | if (ctx->status != STARTED) { | |
127 | mutex_unlock(&ctx->status_mutex); | |
128 | pr_devel("%s: Context not started, failing problem state access\n", __func__); | |
d9232a3d IM |
129 | if (ctx->mmio_err_ff) { |
130 | if (!ctx->ff_page) { | |
131 | ctx->ff_page = alloc_page(GFP_USER); | |
132 | if (!ctx->ff_page) | |
133 | return VM_FAULT_OOM; | |
134 | memset(page_address(ctx->ff_page), 0xff, PAGE_SIZE); | |
135 | } | |
136 | get_page(ctx->ff_page); | |
137 | vmf->page = ctx->ff_page; | |
138 | vma->vm_page_prot = pgprot_cached(vma->vm_page_prot); | |
139 | return 0; | |
140 | } | |
0712dc7e IM |
141 | return VM_FAULT_SIGBUS; |
142 | } | |
143 | ||
144 | vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT); | |
145 | ||
146 | mutex_unlock(&ctx->status_mutex); | |
147 | ||
148 | return VM_FAULT_NOPAGE; | |
149 | } | |
150 | ||
151 | static const struct vm_operations_struct cxl_mmap_vmops = { | |
152 | .fault = cxl_mmap_fault, | |
153 | }; | |
154 | ||
f204e0b8 IM |
155 | /* |
156 | * Map a per-context mmio space into the given vma. | |
157 | */ | |
158 | int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma) | |
159 | { | |
5caaf534 | 160 | u64 start = vma->vm_pgoff << PAGE_SHIFT; |
f204e0b8 | 161 | u64 len = vma->vm_end - vma->vm_start; |
5caaf534 IM |
162 | |
163 | if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { | |
164 | if (start + len > ctx->afu->adapter->ps_size) | |
165 | return -EINVAL; | |
166 | } else { | |
167 | if (start + len > ctx->psn_size) | |
168 | return -EINVAL; | |
169 | } | |
f204e0b8 | 170 | |
0712dc7e IM |
171 | if (ctx->afu->current_mode != CXL_MODE_DEDICATED) { |
172 | /* make sure there is a valid per process space for this AFU */ | |
173 | if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) { | |
174 | pr_devel("AFU doesn't support mmio space\n"); | |
175 | return -EINVAL; | |
176 | } | |
f204e0b8 | 177 | |
0712dc7e IM |
178 | /* Can't mmap until the AFU is enabled */ |
179 | if (!ctx->afu->enabled) | |
180 | return -EBUSY; | |
f204e0b8 IM |
181 | } |
182 | ||
f204e0b8 IM |
183 | pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__, |
184 | ctx->psn_phys, ctx->pe , ctx->master); | |
185 | ||
0712dc7e | 186 | vma->vm_flags |= VM_IO | VM_PFNMAP; |
f204e0b8 | 187 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
0712dc7e IM |
188 | vma->vm_ops = &cxl_mmap_vmops; |
189 | return 0; | |
f204e0b8 IM |
190 | } |
191 | ||
192 | /* | |
193 | * Detach a context from the hardware. This disables interrupts and doesn't | |
194 | * return until all outstanding interrupts for this context have completed. The | |
195 | * hardware should no longer access *ctx after this has returned. | |
196 | */ | |
eda3693c | 197 | int __detach_context(struct cxl_context *ctx) |
f204e0b8 IM |
198 | { |
199 | enum cxl_context_status status; | |
200 | ||
201 | mutex_lock(&ctx->status_mutex); | |
202 | status = ctx->status; | |
203 | ctx->status = CLOSED; | |
204 | mutex_unlock(&ctx->status_mutex); | |
205 | if (status != STARTED) | |
eda3693c | 206 | return -EBUSY; |
f204e0b8 | 207 | |
0b3f9c75 DA |
208 | /* Only warn if we detached while the link was OK. |
209 | * If detach fails when hw is down, we don't care. | |
210 | */ | |
211 | WARN_ON(cxl_detach_process(ctx) && | |
212 | cxl_adapter_link_ok(ctx->afu->adapter)); | |
7bb5d91a MN |
213 | flush_work(&ctx->fault_work); /* Only needed for dedicated process */ |
214 | put_pid(ctx->pid); | |
215 | cxl_ctx_put(); | |
eda3693c | 216 | return 0; |
f204e0b8 IM |
217 | } |
218 | ||
219 | /* | |
220 | * Detach the given context from the AFU. This doesn't actually | |
221 | * free the context but it should stop the context running in hardware | |
222 | * (ie. prevent this context from generating any further interrupts | |
223 | * so that it can be freed). | |
224 | */ | |
225 | void cxl_context_detach(struct cxl_context *ctx) | |
226 | { | |
eda3693c MN |
227 | int rc; |
228 | ||
229 | rc = __detach_context(ctx); | |
230 | if (rc) | |
231 | return; | |
232 | ||
233 | afu_release_irqs(ctx, ctx); | |
eda3693c | 234 | wake_up_all(&ctx->wq); |
f204e0b8 IM |
235 | } |
236 | ||
237 | /* | |
238 | * Detach all contexts on the given AFU. | |
239 | */ | |
240 | void cxl_context_detach_all(struct cxl_afu *afu) | |
241 | { | |
242 | struct cxl_context *ctx; | |
243 | int tmp; | |
244 | ||
ee41d11d IM |
245 | mutex_lock(&afu->contexts_lock); |
246 | idr_for_each_entry(&afu->contexts_idr, ctx, tmp) { | |
f204e0b8 IM |
247 | /* |
248 | * Anything done in here needs to be setup before the IDR is | |
249 | * created and torn down after the IDR removed | |
250 | */ | |
eda3693c | 251 | cxl_context_detach(ctx); |
0712dc7e IM |
252 | |
253 | /* | |
254 | * We are force detaching - remove any active PSA mappings so | |
255 | * userspace cannot interfere with the card if it comes back. | |
256 | * Easiest way to exercise this is to unbind and rebind the | |
257 | * driver via sysfs while it is in use. | |
258 | */ | |
259 | mutex_lock(&ctx->mapping_lock); | |
260 | if (ctx->mapping) | |
261 | unmap_mapping_range(ctx->mapping, 0, 0, 1); | |
262 | mutex_unlock(&ctx->mapping_lock); | |
ee41d11d IM |
263 | } |
264 | mutex_unlock(&afu->contexts_lock); | |
f204e0b8 IM |
265 | } |
266 | ||
8ac75b96 | 267 | static void reclaim_ctx(struct rcu_head *rcu) |
f204e0b8 | 268 | { |
8ac75b96 | 269 | struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu); |
f204e0b8 IM |
270 | |
271 | free_page((u64)ctx->sstp); | |
d9232a3d IM |
272 | if (ctx->ff_page) |
273 | __free_page(ctx->ff_page); | |
f204e0b8 | 274 | ctx->sstp = NULL; |
55e07668 IM |
275 | if (ctx->kernelapi) |
276 | kfree(ctx->mapping); | |
f204e0b8 | 277 | |
52adee58 AD |
278 | if (ctx->irq_bitmap) |
279 | kfree(ctx->irq_bitmap); | |
280 | ||
f204e0b8 IM |
281 | kfree(ctx); |
282 | } | |
8ac75b96 IM |
283 | |
284 | void cxl_context_free(struct cxl_context *ctx) | |
285 | { | |
286 | mutex_lock(&ctx->afu->contexts_lock); | |
287 | idr_remove(&ctx->afu->contexts_idr, ctx->pe); | |
288 | mutex_unlock(&ctx->afu->contexts_lock); | |
289 | call_rcu(&ctx->rcu, reclaim_ctx); | |
290 | } |